Terahertz complex conductivity of cellulose nanocrystal based composite films controlled with PEDOT:PSS blending ratio

Abstract

We investigate the terahertz complex conductivity spectra of cellulose nanocrystal (CNC) based composite films fabricated with different blending ratios of the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and without/with glycerol additive. A partially localized nature of carriers in the composite is clearly seen in the obtained spectral shapes of complex conductivity and is well described by an extended Drude model. We find that the carriers become denser and less localized with increasing PEDOT:PSS blending ratio and that the addition of glycerol to the composite is efficacious in enhancing carrier delocalization as well as mechanical flexibility.